1. Field of the Invention
The present invention relates to a flush toilet apparatus for washing a toilet body with wash water.
2. Description of the Related Art
There is conventionally known a flush toilet apparatus having a jet-pump water supply mechanism as a mechanism for supplying wash water to a toilet body.
This jet-pump water supply mechanism includes a tank that stores therein water, and a jet pump unit is arranged inside of the tank in a submerged state. The jet pump unit includes a throat pipe. One end of the throat pipe is connected to a channel in the direction of the bowl portion of the toilet body, and an opening is formed in the other end thereof. If the water is injected from an injection nozzle into the throat pipe through the opening, then a jet pump action is triggered to cause a large amount of water to flow toward the bowl portion inside of the throat pipe. A large amount of wash water is supplied to the toilet body since not only the water injected from the injection nozzle but also the water stored in the tank is drawn into and flows in the throat pipe.
Meanwhile, in the jet-pump water supply mechanism, there is no need to store all the water to be supplied to the toilet body in the tank as the wash water. This can advantageously make the tank smaller in size than that of a tank water supply mechanism and, therefore, reduce time necessary to fill the tank with water up to a full water level. Furthermore, even if the flush toilet apparatus is installed in an environment in which the water pressure of a water supply pipe is relatively low, it is possible to supply a large amount of wash water to the toilet body. Moreover, the jet-pump water supply mechanism is advantageous in that it is unnecessary to conduct a large-scale construction work, for example, for making the water supply pipe have a large diameter as with a direct-pressure-type flush toilet apparatus.
Furthermore, the shorter time required to fill the tank with water up to the full water level in the jet-pump water supply mechanism can, in turn, improve the continuous washing performance for continuously washing the toilet body. With views of further improving this continuous washing performance, there is known a technique for switching one jet water channel to another to switchably supply the water to the toilet body or to store the water in the tank.
For example, National Publication of International Patent Application No. 2012-528960 describes, as a technique for switching the traveling direction of jet water, a flush toilet apparatus. The flush toilet apparatus has a traveling-direction switching mechanism between a nozzle and a throat pipe, which mechanism allows switchover of the water flow direction to inject water into a throat pipe (supply wash water to a bowl portion) or to pour water into a tank. The traveling-direction switching mechanism includes a float member moving in proportion to the water level of the water stored in the tank, and a shield portion shielding jet water to prevent the jet water injected from the nozzle from flowing into the throat pipe. At a high water level, a buoyant force acts on the shield portion to cause the shield portion to be detached from a suction port of the throat pipe, and the jet water injected from the nozzle flows into the throat pipe with resistance hardly imposed on the jet water. On the other hand, at a low water level, the float member and the shield portion move downward and are located between the nozzle and the throat pipe. This can suppress the entry of the jet water into the throat pipe, whereby the jet water is poured into the tank and stored in the tank.
A flush toilet apparatus described in Japanese Patent No. 4713575 has a traveling-direction switching mechanism arranged downstream of a nozzle, that is, between a nozzle and the throat pipe, which mechanism allows switchover of the water flow direction to inject water into a throat pipe (supply wash water to a bowl portion) or to pour water into a tank. The traveling-direction switching mechanism includes a ball moving vertically in proportion to the water level of the water stored in the tank.
At a high water level, the buoyant force acts on the ball to cause the ball to be detached from the suction port of the throat pipe, and the jet water injected from the nozzle flows into the throat pipe with resistance hardly imposed on the jet water. On the other hand, at a low water level, the ball moves downward and remains between the nozzle and the throat pipe, whereby the jet water is poured into the tank and stored in the tank.
The flush toilet apparatus disclosed in National Publication of International Patent Application No. 2012-528960 is configured to switch the traveling direction of the jet water to store the water in the tank. However, the flush toilet apparatus of National Publication of International Patent Application No. 2012-528960 has the following problems. At a time of switching the toilet washing mode for supplying the jet water to the toilet body to the tank storage mode for storing the water in the tank by switching a jet-water traveling direction, a shield portion shields the jet water. The force of the jet water thereby acts on the shield portion and the shield portion is pressed against the suction port. Owing to this, even if the water level of the tank reaches one at which it is necessary to store the jet water in the tank, then the shield portion remains pressed against the suction port by the jet water, and it is impossible to instantaneously switch the toilet washing mode to the tank storage mode. Furthermore, the interference of the shield portion with the jet water causes the degradation in the jet pump action. As a result, the water that does not contribute to the toilet washing performance and the waste transport performance is supplied in vain to the toilet body, which disadvantageously increases the total flow rate of the water for use in washing.
The flush toilet apparatus disclosed in Japanese Patent No. 4713575 is configured to switch the traveling direction of jet water to store the water in the tank. Japanese Patent No. 4713575 also discloses that the ball shielding the jet water is drawn into the throat pipe by the jet water at the time of switching the toilet washing mode to the tank storage mode. However, the flush toilet apparatus of Japanese Patent No. 4713575 has the following problems. If the jet water strikes against the ball at a time of drawing the ball into the throat pipe, then the jet water striking against the ball travels irregularly, the force of the jet water acts on the ball in all directions, and it is impossible to instantaneously switch the toilet washing mode to the tank storage mode. Furthermore, the jet water which acts to draw the ball into the throat pipe is discharged to the toilet body side through the throat pipe. As a result, similarly to National Publication of International Patent Application No. 2012-528960, the water that does not contribute to the toilet washing performance and the waste transport performance is supplied in vain to the toilet body, which disadvantageously increases the total flow rate of the water for use in washing.